Android实现单页面浮层可拖动view的示例代码

import android.content.Context;import android.support.annotation.AttrRes;import android.support.annotation.NonNull;import android.support.annotation.Nullable;import android.support.v4.widget.ViewDragHelper;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.widget.FrameLayout;import java.util.ArrayList;/** * Created by hq on 2017/10/10. */public class DragFrameLayout extends FrameLayout {  String TAG = "DragFrameLayout";  ViewDragHelper dragHelper;  ArrayList<View> viewList;  public DragFrameLayout(@NonNull Context context) {    this(context, null);  }  public DragFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs) {    this(context, attrs, 0);  }  public DragFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs, @AttrRes int defStyleAttr) {    super(context, attrs, defStyleAttr);    //第二步：创建存放View的集合    viewList = new ArrayList<>();    dragHelper = ViewDragHelper.create(this, 1.0f, new ViewDragHelper.Callback() {      /**       * 是否捕获childView:       * 如果viewList包含child，那么捕获childView       * 如果不包含child，就不捕获childView       */      @Override      public boolean tryCaptureView(View child, int pointerId) {        return viewList.contains(child);      }      @Override      public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {        super.onViewPositionChanged(changedView, left, top, dx, dy);      }      /**       * 当捕获到child后的处理：       * 获取child的监听       */      @Override      public void onViewCaptured(View capturedChild, int activePointerId) {        super.onViewCaptured(capturedChild, activePointerId);        if (onDragDropListener != null) {          onDragDropListener.onDragDrop(true);        }      }      /**       * 当释放child后的处理：       * 取消监听，不再处理       */      @Override      public void onViewReleased(View releasedChild, float xvel, float yvel) {        super.onViewReleased(releasedChild, xvel, yvel);        if (onDragDropListener != null) {          onDragDropListener.onDragDrop(false);        }      }      /**       * 到左边界的距离       */      @Override      public int clampViewPositionHorizontal(View child, int left, int dx) {        return left;      }      /**       * 到上边界的距离       */      @Override      public int clampViewPositionVertical(View child, int top, int dy) {        return top;      }    });  }  /**   * 把要实现拖动的子view添加进来   * @param view   */  public void addDragChildView(View view){    viewList.add(view);  }  @Override  public boolean onInterceptTouchEvent(MotionEvent ev) {    //当手指抬起或事件取消的时候 就不拦截事件    int actionMasked = ev.getActionMasked();    if (actionMasked == MotionEvent.ACTION_CANCEL || actionMasked == MotionEvent.ACTION_UP) {      return false;    }    return dragHelper.shouldInterceptTouchEvent(ev);  }  @Override  public boolean onTouchEvent(MotionEvent event) {    dragHelper.processTouchEvent(event);    return true;  }  public interface OnDragDropListener {    void onDragDrop(boolean captured);  }  private OnDragDropListener onDragDropListener;  public void setOnDragDropListener(OnDragDropListener onDragDropListener) {    this.onDragDropListener = onDragDropListener;  }}

<?xml version="1.0" encoding="utf-8"?><com.windfindtech.hqdemo.view.DragFrameLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:id="@+id/df_content"tools:context="com.windfindtech.hqdemo.MainActivity"><ImageView  android:id="@+id/iv1"  android:layout_width="100dp"  android:layout_height="100dp"  android:src="@mipmap/ic_launcher" /><TextView  android:id="@+id/tv1"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_gravity="center"  android:text="可拖拽文字" /></com.windfindtech.hqdemo.view.DragFrameLayout>

public class MainActivity extends AppCompatActivity {DragFrameLayout m_dragFrameLayout;ImageView m_imageView1;TextView m_textView1;String TAG = "";@Overrideprotected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  m_dragFrameLayout = (DragFrameLayout) findViewById(R.id.df_content);  m_imageView1 = (ImageView)findViewById(R.id.iv1);  m_textView1 = (TextView) findViewById(R.id.tv1);//   m_dragFrameLayout.addDragChildView(m_imageView1);  m_dragFrameLayout.addDragChildView(m_textView1);//具体拖拽动作使用回调即可}}